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<head>
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  <title>Document</title>
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<body>
  <script>
    var num1 = parseInt(prompt('请输入第一个数'))
    
    var num2 = parseInt(prompt('请输入第二个数'))

    alert(num1 + num2)
    alert(num1 + num2 + 10)

  </script>
</body>

</html>